Stereo 3D video support in computing devices

ABSTRACT

Methods are disclosed for supporting stereo 3D video in computing devices. A computing device can receive stereo 3D video data employing a YUV color space and chroma subsampling, and can generate anaglyph video data therefrom. The anaglyph video data can be generated by unpacking the stereo 3D video data to left and right views and combining the left and right views into a single view via matrix transformation. The combining uses transform matrices that correspond to a video pipeline configuration. The transform matrix coefficients can depend on characteristics of the video pipeline components. Modified transform matrix coefficients can be used in response to changes in the video pipeline configuration. Video encoded in stereo 3D video data can be selected to be displayed in stereo 3D, anaglyph or monoscopic form, depending on user input and/or characteristics of video pipeline components.

FIELD

The present disclosure pertains to video processing devices and methods.More particularly, the present disclosure relates to methods ofsupporting stereo 3D video in computing devices.

BACKGROUND

Demand for three-dimensional (3D) video content has increased over thepast several years with the increasing availability of 3D video contentand the ability to generate such content. For example, the number of 3Dmovies, television shows and video games available has greatly increasedover what was available just a few years ago, and many new video capturedevices available on the market have 3D capture capabilities.

Various stereoscopic technologies can be employed to allow a user toexperience 3D video. Most 3D video technologies require the user to weara set of glasses that allow each eye to receive images slightly offsetfrom those received by the other eye. The brain blends the two imagestogether and interprets the differences between them as being the resultof different distances, thus creating the illusion of depth. Oneconventional 3D video technology employs displaying anaglyph images, inwhich two differently filtered color images are superimposed on oneanother to produce the depth effect. Anaglyph video is viewed withglasses comprised of left and right lenses of different colorscorresponding to the color layers in the displayed anaglyph images. Oneform of anaglyph glasses is the well-known white cardboard frame glassescomprising red and blue lenses, which have been used by moviegoers forwell over half a century. The blue lens lets a red image through to oneeye and the red lens lets a blue image through to other eye. Theillusion of depth is created by the offset between the red and blueimages.

In another stereoscopic technology, stereo 3D technology, imagesintended for the left eye and right eye are alternatively shown on adisplay in rapid succession. Stereo 3D video is viewed with shutterglasses that alternatively make the left and right lenses of the glassesgo opaque and transparent in synchronization with the display of leftand right images on the display. That is, the left lens is transparentand the right lens is opaque when a left image is displayed, and theleft lens is opaque and the right lens is transparent when a right imageis displayed. Again, the left and right images are slightly offset fromone another to create the illusion of depth.

One reason anaglyph 3D video has been widely used for so long is its lowcost. Anaglyph glasses are relatively inexpensive and anaglyph video canbe shown on conventional displays with conventional video cards. Incontrast, shutter glasses can cost an order of magnitude or more thananaglyph glasses and high-end displays and premium video cards may beneeded to display and process frames at the increased frame rate neededto display stereo 3D video. Besides increased cost, another disadvantageof stereo 3D video is that shutter glasses are often matched to aparticular brand or type of display. Shutter glasses matched with onedisplay may not allow viewing of stereo 3D video on other displays.

Regardless, demand for stereo 3D is strong as stereo 3D video canprovide higher color quality than anaglyph video. Shutter glassestypically allow substantially the entire color spectrum to betransmitted to each eye and thus do not suffer from the “ghosting” or“crosstalk” that can occur with anaglyph glasses. However, not all usersmay want to spend the money for stereo 3D video hardware. Thus, there isa need to provide users with the ability to view 3D video from a stereo3D video source using conventional technology.

SUMMARY

This Summary is provided to introduce a selection of concepts, in asimplified form, that are further described hereafter in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

Methods are disclosed for supporting stereo 3D video in computingdevices. If a computing device receives stereo 3D video for output at adisplay, the device passes the stereo 3D video data to the display ifthe display is capable of displaying stereo 3D video. If not, theprocessor generates anaglyph video (e.g., non-stereo 3D video) ormonoscopic video (e.g., 2D video) for display.

In one embodiment, a video processor can generate anaglyph video data bycombining left and right views unpacked from stereo 3D video data into asingle anaglyph view. The stereo 3D video data can employ a YUV colorscheme and chroma subsampling, such as 4:2:0 or 4:2:2 chromasubsampling. Anaglyph video data can be generated by performing a matrixtransform on the left and right views. The transform matrices cancorrespond to a video pipeline configuration, and the transform matrixcoefficients can depend on characteristics of components within thepipeline, such as display, video capture device and viewing glassescharacteristics. Original equipment manufacturers can supply modifiedanaglyph transform matrix coefficients that are tuned to specific videocomponents used in different video pipeline configurations. Thesemodified anaglyph transform matrix coefficients can be supplied to thecomputing device and used in generating anaglyph video data.

In another embodiment, the user can select the format of the videooutput at the display. The selected video display format can be stereo3D, anaglyph or monoscopic video. This selection can be based oncharacteristics of a display or viewing glasses, or user input. The usercan select a video display format in response to a query presented bythe computing device, or independent of device prompt.

The foregoing and other objects, features and advantages of theinvention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram depicting an exemplary computing device.

FIG. 2 illustrates a generalized example of a suitable implementationenvironment in which described embodiments, techniques, and technologiesmay be implemented.

FIG. 3 is a block diagram of an exemplary video pipeline.

FIGS. 4( a)-4(e) show various chroma sampling schemes and chromasampling arrangements.

FIG. 5 is a flowchart of an exemplary method of selecting a videodisplay format.

FIGS. 6( a)-6(b) show exemplary generation of anaglyph video data fromstereo 3D video data using 4:2:0 and 4:2:2 chroma subsampling.

FIG. 7 is a flowchart of an exemplary method of generating anaglyphvideo data from stereo 3D video data.

DETAILED DESCRIPTION

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Similarly, the word “or” is intended to include“and” unless the context clearly indicates otherwise. The term“comprising” means “including;” hence, “comprising A or B” meansincluding A or B, as well as A and B together. Additionally, the term“includes” means “comprises.”

FIG. 1 is a system diagram depicting an exemplary computing device 100that can be used to perform any of the methods described herein.Generally, components 105 in the computing device 100 can communicatewith other components, although not all connections are shown, for easeof illustration. The computing device 100 can include a variety ofoptional hardware and software components 105. The computing device canbe any of a variety of mobile or non-mobile computing devices (e.g.,smartphone; handheld, netbook, notebook, tablet or desktop computer;Personal Digital Assistant (PDA); server) and can allow wireless two-waycommunications with one or more mobile communications networks 107, suchas a cellular or satellite network.

The illustrated computing device 100 can include a controller orprocessor 110 (e.g., signal processor, graphics processing unit (GPU),microprocessor, ASIC, or other control and processing logic circuitry orsoftware) for performing such tasks as signal coding, graphicsprocessing, data processing, input/output processing, power control,and/or other functions. An operating system 112 can control theallocation and usage of the components 105 and support for one or moreapplication programs 114. The application programs can include commonmobile computing applications (e.g., email applications, calendars,contact managers, web browsers, messaging applications), or any othercomputing application.

The illustrated computing device 100 can include memory 120. Memory 120can include non-removable memory 122 and removable memory 124. Thenon-removable memory 122 can include RAM, ROM, flash memory, a harddrive, or other well-known memory storage technologies. The removablememory 124 can include flash memory cards (e.g., SD (Secure Digital)cards), memory sticks, a Subscriber Identity Module (SIM) card, which iswell known in GSM (Global System for Mobile Communication) systems, orother well-known memory storage technologies, such as “smart cards.” Thememory 120 can be used for storing data and/or computer-executableinstructions for running the operating system 112 and the applications114. Example data can include web pages, text, images, sound files,video data or other data sets to be sent to and/or received from one ormore network servers or other devices by the computing device 100 viathe one or more wired or wireless networks 107. The memory 120 can beused to store a subscriber identifier, such as an International MobileSubscriber Identity (IMSI), and an equipment identifier, such as anInternational Mobile Equipment Identifier (IMEI). Such identifiers canbe transmitted to a network server to identify users and equipment. Thecomputing device 100 can also have access to external memory 126, whichcan comprise, for example, an external hard drive or any memory storeaccessible to the computing device 100 over a wired or wireless local ornetwork connection.

The computing device 100 can support one or more input devices 130, suchas a touch screen 132, microphone 134, camera 136, physical keyboard 138and trackball 139 and one or more output devices 140, such as a speaker142, a display 144 and 3D viewing glasses 146 (e.g., anaglyph or shutterglasses). The camera 136 can be a video capture device capable ofcapturing and generating 3D images or video. Other possible outputdevices (not shown) can include piezoelectric or other haptic outputdevices. Any of the input devices 130 and output devices 140 can beinternal to, external to, or removably attachable with, the computingdevice 100. External input and output devices 130 and 140 cancommunicate with the computing device 100 via wired or wireless networkconnections. Some devices can serve more than one input/output function.For example, touch screen 132 and display 144 can be combined in asingle input/output device.

A wireless modem 160 can be coupled to a wireless modem antenna 162 andcan support two-way communications between the computing device 100 andexternal devices, as is well understood in the art. The modem 160 andthe antenna 162 are shown generically and can be a wireless cellularmodem for communicating with a mobile cellular communication network.The wireless modem 160 can comprise other radio-based modems such as aWi-Fi modem 163 or a Bluetooth modem 164, each of which can be coupledto its own antenna (e.g., Wi-Fi antenna 168, Bluetooth antenna 169). Thewireless modem 160 is typically configured for communication with one ormore cellular networks, such as a GSM network for data and voicecommunications within a single cellular network, between cellularnetworks, or between the computing device and a public switchedtelephone network (PSTN).

The computing device 100 can further include at least one input/outputport 170 (which can be, for example, a USB port, IEEE 1394 (FireWire)port, and/or RS-232 port) comprising physical connectors 172, a powersupply 174, a satellite navigation system receiver such as a GPSreceiver 175, a gyroscope 176, an accelerometer 177 and a compass 178.The GPS receiver 175 can be coupled to a GPS antenna 179. The computingdevice 100 can additionally include an AM/FM antenna 180 coupled to anAM/FM receiver 185 for receiving radio signals broadcast by an AM/FMradio signal transmitter. The computing device 100 can further includeone or more additional antennas 190 coupled to one or more additionalreceivers, transmitters and/or transceivers 195 to enable variousadditional functions. For example, computing device 100 can include anadditional antenna 190 coupled to an additional receiver 195 configuredto receive and process a digital audio radio service (DARS) signal foroutput at the computing device 100 or an attached accessory.

Although the various antennas are shown as separate hardware componentsof the computing device 100, they can be incorporated into othercomponents. For example, GPS antenna 179 can be incorporated into theGPS receiver 175. In addition, antennas shown as separate in FIG. 1 canbe implemented as a single antenna. For example, the AM/FM antenna 180and the GPS antenna 179 can be a single antenna shared by GPS receiver175 and AM/FM receiver 185. Furthermore, multiple antennas can beconnected to a switch to allow a component to be coupled to one ofseveral antenna sources, or to more than one antenna source. Forexample, the AM/FM receiver 185 can be connected to a switch (not shown)that allows either the AM/FM antenna 180 or an antenna external to thecomputing device 100 to be used as the AM/FM receiver antenna source.The switch can also be configured to allow both the AM/FM antenna 180and an external antenna, or multiple external antennas to besimultaneously used as antenna sources for the AM/FM receiver 185.

The illustrated components 105 are not required or all-inclusive, as anycomponents can be deleted and other components can be added.

FIG. 2 illustrates a generalized example of a suitable implementationenvironment 200 in which described embodiments, techniques, andtechnologies may be implemented.

In example environment 200, various types of services (e.g., computingservices) are provided by a cloud 210. For example, the cloud 210 cancomprise a collection of computing devices, which may be locatedcentrally or distributed, that provide cloud-based services to varioustypes of users and devices connected via a network such as the Internet.The implementation environment 200 can be used in different ways toaccomplish computing tasks. For example, some tasks (e.g., processinguser input and presenting a user interface) can be performed on localcomputing devices (e.g., connected devices 230, 240, 250) while othertasks (e.g., storage of data to be used in subsequent processing) can beperformed in the cloud 210.

In example environment 200, the cloud 210 provides services forconnected devices 230, 240, 250 with a variety of screen capabilities.Connected device 230 represents a device with a computer display 235(e.g., a mid-size display). For example, connected device 230 could be adesktop, laptop, notebook, netbook or tablet computer or the like.Connected device 240 represents a computing device with a computingdevice display 245 (e.g., a small-size display). For example, connecteddevice 240 could be a mobile phone, smart phone, personal digitalassistant or the like. Connected device 250 represents a device with alarge display 255. For example, connected device 250 could be atelevision with Internet connectivity, or a television connected toanother device capable of connecting to the cloud such as a set-top box,gaming console or the like. One or more of the connected devices 230,240, 250 can include touch screen capabilities. Devices without displaycapabilities also can be used in example environment 200. For example,the cloud 210 can provide services for one or more computers (e.g.,server computers) without displays.

Services can be provided by the cloud 210 through service providers 220,or through other providers of online services (not depicted). Forexample, cloud services can be customized to the display size, displaycapability, and/or touch screen capability of a particular connecteddevice (e.g., connected devices 230, 240, 250). Services that can beprovided by the service providers 220 include, for example, email, ShortMessage Service (SMS), Multimedia Message Service (MMS), socialnetworking, website hosting and the provision of 3D video content. Theservice providers can host online marketplaces offering wide varietiesof goods and services such as software applications and upgrades andmedia content which can be obtained by users with or without purchaseand for download from the cloud or delivery through postal mail.

In example environment 200, the cloud 210 provides the technologies andsolutions described herein to the various connected devices 230, 240,250 using, at least in part, the service providers 220. For example, theservice providers 220 can provide a centralized solution for variouscloud-based services. The service providers 220 can manage servicesubscriptions for users and devices (e.g., for the connected devices230, 240, 250 and their respective users).

FIG. 3 shows a block diagram of an exemplary video pipeline 300 that canbe used to implement the various methods described herein. The videopipeline 300 comprises a stereo 3D video source 310, a video processor320 and a display 330. Any video pipeline component can be internal orexternal to a specific computing device. For example, a video recorder,the video processor 320 and the display 330 can be integrated into alaptop computer, tablet computer or smartphone. In another example, thevideo processor 320 can be internal to a desktop computer, the stereo 3Dvideo source can be a portable handheld video recorder connectable tothe desktop computer, and the display 330 can be external to thedesktop. In still another example, a stereo 3D video source (e.g., awebcam) 310 can be integrated into a laptop computer, the videoprocessor 320 can be a service provided by a cloud-based serviceprovider, and the display 330 can be a remote display relative to thelaptop computer, such as a television. Although not shown, 3D viewingglasses (e.g., shutter glasses, anaglyph glasses) are also consideredpart of the video pipeline.

The stereo 3D video source 310 can be a source that provides orgenerates stereo 3D video data 340. The stereo 3D video source 310 canbe, for example, a video capture device such as a handheld camera, videorecorder or webcam, internal or external memory, or a cloud-basedservice provider. Stereo 3D video data 340 and 350 can be a data thatcan be used for generating separate left and right images that, whenviewed on a display, create the illusion of depth. Stereo 3D video data340 and 350 can be used to generate time-multiplexed left and rightimages that are alternatively displayed on the display 330 in rapidsuccession, or to generate spatially-multiplexed left and right imagesthat are displayed simultaneously and adjacent to each other (i.e., theleft and right images are displayed side-by-side (horizontally tiled) orone above the other (vertically tiled)).

The stereo 3D video data 340 and 350 can conform to any stereo 3D videostandard. For example, the stereo 3D video data 340 and 350 can conformto the H.264/MPEG-4 Part 10 codec standard, which uses a YUV color spaceand employs chroma subsampling. As used herein, a YUV color space refersto any color space that can be described in terms of a single brightnesscomponent (Y) and two color components (UV). Thus, a YUV color space canrefer, for example, to YCbCr, YPbPr color spaces and to any number ofYUV pixel formats such as YUY2, NV12, UVUY, etc. In addition, each YUVcomponent can represent a value that is or is not gamma-compressed. Forexample, a YUV color space can refer to Y′UV color space in which thebrightness component is a luma value Y′ which is a gamma-compressedversion of a luminance value Y.

Video compression standards that employ chroma subsampling, such as theH.264 standard, take advantage of the fact that the human eye is moresensitive to changes in brightness than to changes in color to encodecolor video at a reduced bitrate. Generally, a chroma subsampling schemecan be expressed as a three-part ratio J:a:b that describes the numberof luma and chroma samples in a conceptual region J pixels wide and 2pixels high. In general, “a” represents the number of chroma samplestaken in the first row of pixels in the conceptual region, and “b”represents the number of additional chroma samples in the second row ofpixels.

FIGS. 4( a)-4(e) show various chroma sampling schemes and chromasampling arrangements for a conceptual region 4 pixels wide (J=4) and 2pixels wide, the conceptual region size typically used in describingchroma sampling schemes. Image pixels, the pixels that are part of animage output at a display, are represented by boxes with thin lines.Chroma sampling regions, the regions in which a single chroma sample istaken, are represented by boxes with thick lines. The dots indicatewhere a chroma sample is taken within a chroma sample region. In FIGS.4( a)-4(d), the chroma sampling regions are aligned with the imagepixels. That is, the chroma sampling region boundaries coincide withimage pixel boundaries. In each chroma sampling scheme, eight lumasamples are taken within a 4×2 pixel conception region, one for eachimage pixel.

FIG. 4( a) shows a 4:4:4 chroma sampling scheme 410, such as that usedin an encoding employing the RGB color space. In an RGB encoding, red,green and blue samples are taken at each image pixel. Four chromasamples are taken along the first row of the conceptual region, andanother four chroma samples are taken along the second row of theconceptual region. Thus, for each 4:4:4 conceptual region, three colorsamples are taken at eight locations for a total of 24 samples.

FIG. 4( b) shows a 4:2:0 chroma subsampling scheme 420 used in anencoding using a YUV color space. In a 4:2:0 chroma subsampling, twochroma samples are taken along the first row of pixels, and noadditional chroma samples are taken in the second row of pixels. Thus,four chroma samples (2 U,V chroma sample pairs) are taken in eachconceptual region, a first U,V chroma sample pair for the four left-mostimage pixels, and a second U,V chroma sample pair for the fourright-most image pixels. Thus, twelve total samples are taken in the4:2:0 chroma subsampling scheme for each 4×2 pixel region—8 luma samplesand 4 chroma samples.

FIG. 4( c) shows a 4:2:2 chroma subsampling scheme 430. Two chromasamples are taken along the first row of the conceptual region, and anadditional two chroma samples are taken along the second row of theconceptual region. Thus, eight chroma samples (4 U,V chroma samplepairs) are taken in each eight-pixel region, giving a total of 16samples—8 luma samples and 8 chroma samples.

Accordingly, the 4:2:0 and 4:2:2 chroma subsampling schemes allow imagesand video to be represented with one-half and two-thirds the number ofbits, respectively, relative to that needed in a 4:4:4 chroma samplescheme. Thus, video data encoded using a YUV color space and chromasubsampling provides for the delivery of color images or video at areduced bitrate relative to video data encoded using the RGB colorspace.

FIGS. 4( a)-4(c) show “centered” chroma sampling arrangements in whichchroma samples are taken at the centroid of their respective chromasampling regions. For example, with reference to FIG. 4( b), the U,Vsamples are taken in the center of the chroma sampling region, which isat the middle of the four corresponding image pixels. Other,“non-centered” chroma sampling arrangements exist, and the methodsdescribed herein can work with any chroma sampling arrangement.

FIG. 4( d) shows a non-centered chroma sampling arrangement 440 for a4:2:0 chroma subsampling scheme in which the chroma samples are taken inthe upper left-most image pixel within a chroma sampling region.Although FIGS. 4( a)-4(d) show chroma sampling schemes in which thechroma sampling regions are aligned with image pixels, the methodsdescribed herein can be used with “non-aligned” chroma samplingarrangements. Chroma sampling regions can be offset from image pixels,such as the chroma sampling arrangement 450 shown in FIG. 4( e).

The video processor 320 is capable of receiving stereo 3D video data340, generating anaglyph video data 360 or monoscopic video data 370from the stereo 3D video data 340, and transmitting stereo 3D video data350, anaglyph video data 360 or monoscopic video data 370 to the display330. The video processor 320 can be implemented in hardware or softwareand can be integrated into a computing device or display 330, or beprovided by a cloud-based service. Within a computing device, the videoprocessor can be integrated into the controller 110 or the operatingsystem 112, or be a stand-alone hardware or software component.

The video processor 320 can detect that received video data comprisesstereo 3D video 340 data by examining the contents of the received videodata. For example, the video processor 320 can comprise an H.264 decoderthat determines whether the received data is H.264 compliant. If thevideo processor 320 detects H.264-compliant video, it can look to anysupplemental enhancement information (SEI) to gain additionalinformation about the data. For example, SEI with payload 22 containsstereo video information and SEI with payload 25 contains frame packinginformation. These payloads can provide information about the stereo 3Dnature of the video data such as which field or frame is for which view(left/right).

The video processor 320 can also process stereo 3D video data conformingto Multiview Video Coding (MVC) features of the H.264 standard.Multiview Video Coding is an amendment to the H.264 standard that allowsfor the encoding of video captured simultaneously from multiple cameras.Multiview Video Coding comprises the Multiview High Profile, whichsupports an arbitrary number of views, and the Stereo High Profile,which supports two views.

The video processor 320 can receive user input indicating informationabout the stereo 3D video data 340 and 350. For example, if the videoprocessor 320 passes stereo 3D video data 350 to the display 330, and aviewer sees two videos arranged adjacent to each other, the viewer canprovide this information to the computing device through a userinterface. For example, the user can provide input to the computingdevice indicating that the display 330 is showing videos that arehorizontally or vertically tiled.

In addition to receiving video data and detecting the presence of stereo3D video data, the video processor can select a video data format to beused when transmitting video data to the display 330. For example, thevideo processor 320 can select stereo 3D, anaglyph or monoscopic videoformat. If the video processor selects stereo 3D video, the videoprocessor can pass the received stereo 3D video data 340 through to thedisplay 330 in the same stereo 3D video format, or convert the receivedstereo 3D video data 340 to another stereo 3D video format. As usedherein, the term “video data format” refers to a format of data encodingvideo, while the term “video display format” refers to the format of thevideo output at a display. Thus, for example, data encoding video in astereo 3D video data format can be used to generate video that is outputat a display in a stereo 3D video display format.

Alternatively, the video processor 320 can select a non-stereo 3D videodisplay format (e.g., anaglyph or monoscopic) for display in a videoencoded in stereo 3D video data 340. The video processor 320 can makethis selection based on, for example, capabilities of the display 330and/or user input 340. For example, the video processor 320 can selectthe video display format based on whether the display 330 is capable ofdisplaying stereo 3D video.

Stereo 3D video may not be able to be output at a display 330 forvarious reasons. For example, the display 330 may not have a high enoughrefresh rate for displaying time-multiplexed stereo 3D video. Also,other hardware or software component in the video pipeline 300downstream from the video processor (e.g., video card, device drivers)may not support stereo 3D video. The video processor 320 can determinewhether stereo 3D video can be viewed at the display 330 by queryingthese downstream components of their abilities, or by being notified bya downstream component that an attempt to process stereo 3D video foroutput at the display 330 has failed. For example, the video processor320 can attempt to allocate and prepare output video buffers beforeprocessing a stereo 3D video frame. If the video processor 320 is unableto allocate stereo 3D video buffers due to hardware or softwareshortcomings of the video pipeline, it can determine that stereo 3Dvideo cannot be output at the display 330.

In addition, the video processor 320 can select a video display formatbased on whether 3D viewing glasses are within communication range ofthe computing device or display 330. For example, stereo 3D viewingglasses can be configured to transmit data to the display 330 or acomputing device indicating that the glasses are within communicationrange of the display. The glasses could send this signal at varioustimes such when the glasses are turned on, at periodic intervals or inresponse to receiving synchronization signals from the display 330.

The video processor can also select a video display format based on userinput. In some embodiments, the computing device can query a user toselect a video display format at the display 330. If stereo 3D video canbe output at the display 330, the query can ask the user to select fromamong two or more of the following video display formats: stereo 3D,anaglyph or monoscopic video. If stereo 3D video cannot be displayed atthe display 330, the query can ask the user to select between anaglyphand monoscopic video. The query can be presented to the user at thedisplay 330 or at any user interface accessible to the computing device.The query can be made when, for example, the video processor 320 firstreceives stereo 3D video data 340, or each time stereo 3D video data 340is received. In addition, the user can select a video display format inindividual software applications or by setting system-level parameterssuch as a parameter of the operating system. Further, the user canselect a video display format without being queried by the computingdevice. For example, a user watching 3D video by himself can selectmonoscopic video if several friends arrive and there are not enough 3Dviewing glasses to go around, and then select anaglyph or stereo 3Dvideo after his friends leave. If anaglyph or monoscopic video isselected, the video processor 320 converts the stereo 3D video data 340to anaglyph video data 360 or monoscopic video 370. If stereo 3D videodata is selected, the video processor passes the stereo 3D video data340 through to the display 330 as stereo 3D video data 350.

FIG. 5 is a flowchart of an exemplary method 500 for selecting a videodisplay format. The method 500 can be executed, for example, by a laptopcomputer outputting 3D video captured by an external video recorder on atelevision. At 510, stereo 3D video data employing a YUV color space isreceived at a computing device. In the example, the laptop computerreceives stereo 3D video data captured by a video recorder. The receivedvideo data can be “live” video streamed from the recording device orstored video data previously captured. The stereo 3D video is encodedusing a YUV color space. At 520, the video display format is selectedfrom at least two of the following formats: stereo 3D video, anaglyphvideo and monoscopic video. In the example, the user selects anaglyphvideo from among a list of stereo 3D, anaglyph and monoscopic videodisplay formats presented to him as a query shown at the laptop displayor the television. At 530, the video encoded in the stereo 3D video datais displayed in the selected video display format. In the example, thevideo captured by the video capture device is displayed to the user atthe television in anaglyph form.

FIG. 6( a) shows an exemplary generation of anaglyph video data 610 fromstereo 3D data employing a YUV color space and 4:2:0 chroma subsampling.A video processor can generate the YUV 4:2:0 anaglyph video data 610 byunpacking the stereo 3D video YUV 4:2:0 data to left view data 620 andright view data 630 and then combining the left and right view data 620and 630 into a single anaglyph view, or anaglyph video data 610. The YUV4:2:0 anaglyph data 610 can generated using the following equation:

${\begin{pmatrix}{Y\; 0} \\{Y\; 1} \\{Y\; 2} \\{Y\; 3} \\U \\V\end{pmatrix} = {{{ML\_}420\begin{pmatrix}{{YL}\; 0} \\{{YL}\; 1} \\{{YL}\; 2} \\{{YL}\; 3} \\{UL} \\{VL}\end{pmatrix}} + {{MR\_}420\begin{pmatrix}{{YR}\; 0} \\{{YR}\; 1} \\{{YR}\; 2} \\{{YR}\; 3} \\{UR} \\{LR}\end{pmatrix}}}},$Wherein YL0-YL3 are luma samples of the left view, UL and VL are chromasamples of the left view; YR0-YR3 are luma samples of the right view; URand VR are chroma samples of the right view, Y0-Y3 are luma samples ofthe anaglyph video data; and U and V are chroma samples of the anaglyphvideo data; ML_(—)420 and MR_(—)420 are anaglyph transform matriceshaving the form:

${{{Mx\_}420} = \begin{pmatrix}a & 0 & 0 & 0 & b & c \\0 & a & 0 & 0 & b & c \\0 & 0 & a & 0 & b & c \\0 & 0 & 0 & a & b & c \\{d\; 0} & {d\; 1} & {d\; 2} & {d\; 3} & e & f \\{g\; 0} & {g\; 1} & {g\; 2} & {g\; 3} & h & i\end{pmatrix}},$wherein a, b, c, d0-d3, e, f, g0-g3, h and i are anaglyph transformmatrix coefficients. The resulting YUV 4:2:0 anaglyph video data 610 canhave the correct minimum display aperture as well as pixel aspect ratioto be displayed correctly on the display. In the case of Multiview VideoCoding, there is no need to adjust the pixel aspect ratios. The correctrendering of the anaglyph frames can depend on the rendering engine tohonor aspect ratios and other flags contained in the video data for theframes. The d0-d3 and g0-g3 transform matrix coefficients depend on thechroma sampling arrangement. In some embodiments, the chroma values arescaled to be in the [−128,127] range.

In one embodiment, the following ML_(—)420 and MR_(—)420 anaglyphtransform matrices can be used for generating anaglyph video data fromstereo 3D video encoded using the ITU-R (International TelecommunicationUnion Radiocommunication Sector) Recommendation BT.709 color gamut:

$M_{L\; 420} = \begin{pmatrix}0.13 & 0 & 0 & 0 & 0.025 & 0.043 \\0 & 0.13 & 0 & 0 & 0.025 & 0.043 \\0 & 0 & 0.13 & 0 & 0.025 & 0.043 \\0 & 0 & 0 & 0.13 & 0.025 & 0.043 \\{- 0.027} & {- 0.027} & {- 0.027} & {- 0.027} & 0.0072 & {- 0.042} \\0.18 & 0.18 & 0.18 & 0.18 & 0.18 & 0.24\end{pmatrix}$ $M_{R\; 420} = \begin{pmatrix}0.86 & 0 & 0 & 0 & 0.10 & 0.14 \\0 & 0.86 & 0 & 0 & 0.10 & 0.14 \\0 & 0 & 0.86 & 0 & 0.10 & 0.14 \\0 & 0 & 0 & 0.86 & 0.10 & 0.14 \\0.027 & 0.027 & 0.027 & 0.027 & 1.26 & {- 0.083} \\{- 0.18} & {- 0.18} & {- 0.18} & {- 0.18} & {- 0.085} & {- 0.11}\end{pmatrix}$

The anaglyph transform matrices (e.g., ML_(—)420, MR_(—)420) cancorrespond to a specific video pipeline configuration. A video pipelineconfiguration corresponds to a combination of video pipeline componentsand settings of these components. For example, one video pipelineconfiguration can correspond to a stereo 3D video source, display andviewing glasses combination supplied with a laptop computer. Theanaglyph transform matrix coefficients can depend on characteristics ofcomponents within a video pipeline configuration. For example, theanaglyph transform matrix coefficients can be based on one or more ofthe following: chroma sampling scheme, chroma sampling arrangement,video capture device characteristics, display characteristics andviewing glasses characteristics. For example, different video capturedevices and displays can have different color gamuts, anaglyph glassescan have lenses of various color combinations (e.g., red-blue,red-green, red-cyan, green-magenta), and video capture devices cansample chroma values using various chroma sampling arrangements and canhave varying color gamuts.

The anaglyph transform matrix coefficients can be set to default ormodified coefficients. The default coefficients can correspond togeneral values that work for a range of video pipeline components, orfor a default video pipeline configuration (e.g., a video pipelineconfiguration supplied with a computing device). For example, an OEM(original equipment manufacturer) desktop computer manufacturer candetermine a set of default anaglyph transform matrix coefficients thataccount for the color gamuts or spectrums used by a display and a cameraintegrated into the desktop.

The modified coefficients can correspond to a change in a video pipelineconfiguration. That is, any change in the chroma sampling scheme, chromasampling arrangement, stereo 3D video source, display or viewing glassescan result in modified anaglyph transform matrix coefficients being usedto generate anaglyph video data. These modified coefficients can besupplied, for example, by the stereo 3D video source, display or glasses(e.g., stored in memory in these components and provided to thecomputing device upon connection of a component to the computing device)or by the computing device accessing the cloud and downloading themodified coefficient coefficients from an OEM or retailer web site.

The modified coefficients can be supplied by a user, an application, theoperating system, a display, viewing glasses or stereo 3D video sourceaccessing application program interfaces (APIs) exposed by the videoprocessor 320. The default or modified coefficients can also be suppliedby setting operating system parameters accessible to the video processor320. In some embodiments, no translation or mapping is needed to makethe modified coefficients compatible with the specific stereo 3D videodata to anaglyph video data conversion. For example, for the generationof anaglyph YUV 4:2:0 video data from stereo 3D YUV 4:2:0 video data,the modified coefficients comprise one or more of the coefficients a, b,c, d0-d3, e, f, g0-g3, h and i used in the ML_(—)420 and MR_(—)420transform matrices described above.

Modified anaglyph transform matrix coefficients can be provided frommultiple sources. For example, one or more modified coefficients can besupplied due to a stereo 3D video source change and one or more othermodified coefficients could be provided due to a display change.Moreover, multiple modified coefficients can be provided for a singleanaglyph transform matrix coefficient. For example, a change in thedisplay and a change in the viewing glasses can result in modifiedcoefficients being supplied for the same anaglyph transform matrixcoefficient. In this case, the video processor can generate a newmodified coefficient based on the multiple modified coefficientsreceived.

The video processor 320 can map default or modified anaglyph transformmatrix coefficients for use in generating anaglyph video data using afirst color space and chroma sampling combination to coefficients foruse in generating anaglyph video data using a second color space andchroma sampling combination. For example, if the video processor 320 issupplied with coefficients for use in generating anaglyph video using aYUV color space and 4:4:4 chroma sampling combination from stereo 3Dvideo data that uses a YUV color space and 4:4:4 chroma sampling aswell, the anaglyph video data can be generated according to the

${\begin{pmatrix}Y \\U \\V\end{pmatrix} = {{{ML\_}444\begin{pmatrix}{YL} \\{UL} \\{VL}\end{pmatrix}} + {{MR\_}444\begin{pmatrix}{YR} \\{UR} \\{VR}\end{pmatrix}}}},$wherein YL, UL and VL are chroma samples of stereo 3D left view data;YR, UR and VR are chroma samples of the stereo 3D right view data; Y, Uand V are chroma samples of the anaglyph video data; and ML_(—)444 andMR_(—)444 are anaglyph transform matrices having the form:

${{{Mx\_}444} = \begin{pmatrix}a & b & c \\d & e & f \\g & h & i\end{pmatrix}},$wherein a-i are anaglyph transform matrix coefficients.

The video processor 320 can transform the Mx_(—)444 transform matrixcoefficients to Mx_(—)420 transform matrix coefficients for generatinganaglyph video data using 4:2:0 chroma subsampling. The transformationcan accounting for the differences in the 4:4:4 and 4:2:0 chromasampling schemes and the chroma sampling arrangement used. For example,generation of the Mx_(—)420 transform matrix chroma coefficients (d0-d3,e, f, g0-g3, h and i) includes scaling the Mx_(—)444 chroma transformmatrix coefficients downward to account for the fact that each 4:2:0chroma sample corresponds to four 4:4:4 chroma samples. In someembodiments, the sum of the Mx_(—)420 chroma coefficients add up totheir corresponding Mx_(—)444 chroma coefficient (i.e., d0+d1+d2+d3=d;g0+g1+g2+g3=g). If the Mx_(—)444 and Mx_(—)420 matrix coefficientscorrespond to chroma sampling arrangements in which the chroma samplesare taken at the center of the chroma sampling regions, thend0=d1=d2=d3=d/4 and g0=g1=g2=g3=g/4. The values of d0-d3 and g0-g3 canvary with different chroma sampling arrangements.

FIG. 7 is flowchart of an exemplary method 700 of displaying anaglyphvideo in place of stereo 3D video. The method 700 can be executed, forexample, by a laptop computer streaming stereo 3D video from acloud-based service provider. At 710, stereo 3D video data employing aYUV color space is received. In the example, the laptop is streaming a3D movie encoded in a stereo 3D video display format and employing a YUVcolor space, from the cloud-based service provider. At 720, anaglyphvideo data is generated from the stereo 3D video data using a computingdevice. In the example, the desktop generates anaglyph video from thestereo 3D video data. The generation of anaglyph data comprises, at 730,unpacking the stereo 3D video data to a left view and a right view, and,at 740, combining the left and right views into a single view. Theanaglyph video data comprises the single view. In the example, thelaptop unpacks the stereo 3D video data into left and right views andcombines them into a single view. At 750, the video encoded in thestereo 3D video data is displayed in anaglyph form. In the example, thestreamed movie is displayed at the laptop display in anaglyph form.

FIG. 6( b) shows an exemplary generation of anaglyph video data 650 fromstereo 3D data employing a YUV color space and 4:2:2 chroma subsampling,such as stereo 3D video data complying with the H.264 standard FidelityRange Extensions. Anaglyph video data 650 employing a YUV color spaceand using 4:2:2 chroma subsampling can be generated from left view data660 and right view data 670 unpacked from the stereo 3D video data usingthe following equation:

${\begin{pmatrix}{Y\; 0} \\{Y\; 1} \\U \\V\end{pmatrix} = {{{ML\_}422\begin{pmatrix}{{YL}\; 0} \\{{YL}\; 1} \\{UL} \\{VL}\end{pmatrix}} + {{MR\_}422\begin{pmatrix}{{YR}\; 0} \\{{YR}\; 1} \\{UR} \\{VR}\end{pmatrix}}}},$wherein YL0 and YL1 are luma samples of the left view data, UL and VLare chroma samples of the left view data, YR0 and YR1 are luma samplesof the right view data, UR and VR are chroma samples of the right viewdata, Y0 and Y1 are luma samples of the anaglyph video data, U and V arechroma samples of the anaglyph video data; and ML_(—)422 and MR_(—)422are anaglyph transform matrices having the form:

${{{Mx\_}422} = \begin{pmatrix}a & 0 & b & c \\0 & a & b & c \\{d\; 0} & {d\; 1} & e & f \\{g\; 0} & {g\; 1} & h & i\end{pmatrix}},$wherein a, b, c d0, d1, e, f, g0-g1, h and i are anaglyph transformmatrix coefficients.

Although generation of anaglyph video data 610 and 650 encoded using aYUV color space and using 4:2:2 or 4:2:0 chroma subsampling schemes arediscussed herein, the disclosed methods are not limited thereby. Thevideo processor 320 can generate anaglyph data from stereo 3D video datausing other chroma sampling schemes, chroma sampling arrangements oremploying other color spaces in a similar fashion.

Returning to FIG. 3, the display 330 can be a display that is accessibleto a computing device. The display 330 can be an integrated display suchas a smartphone touch screen or a laptop LCD display, an externalmonitor or television in communication with the computing device, or anyremote display accessible to the computing device via the cloud. Thedisplay 330 can comprise any video pipeline hardware and softwarelocated downstream from the video processor 320. For example, thedisplay can include device drivers, video cards, rendering engines,digital signal processors, graphics processing units and the like.

Any of the computer-executable instructions for implementing thedisclosed techniques as well as any data created and used duringimplementation of the disclosed embodiments can be stored on one or morecomputer-readable media (e.g., non-transitory computer-readable media,such as one or more optical media discs, volatile memory components(e.g., DRAM or SRAM), or nonvolatile memory components (e.g., as flashmemory or hard drives)) and executed on a computer (e.g., anycommercially available computer, including smart phones or other mobilecomputing devices that include computing hardware). Thecomputer-executable instructions can be part of, for example, adedicated software application or a software application that isaccessed or downloaded via a web browser or other software applications(such as a remote computing application). Such software can be executed,for example, on a single local computer (e.g., any suitable commerciallyavailable computer) or in a network environment (e.g., via the Internet,a wide-area network, a local-area network, a client-server network (suchas a cloud computing network), or other such network) using one or morenetwork computers.

For clarity, only certain selected aspects of the software-basedimplementations are described. Other details that are well known in theart are omitted. For example, it should be understood that the disclosedtechnology is not limited to any specific computer language or program.For instance, the disclosed technology can be implemented by softwarewritten in C++, Java, Perl, JavaScript, Adobe Flash, or any othersuitable programming language. Likewise, the disclosed technology is notlimited to any particular computer or type of hardware. Certain detailsof suitable computers and hardware are well known and need not be setforth in detail in this disclosure.

Furthermore, any of the software-based embodiments (comprising, forexample, computer-executable instructions for causing a computer toperform any of the disclosed methods) can be uploaded, downloaded, orremotely accessed through a suitable communication means. Such suitablecommunication means include, for example, the Internet, the World WideWeb, an intranet, software applications, cable (including fiber opticcable), magnetic communications, electromagnetic communications(including RF, microwave, and infrared communications), electroniccommunications, or other such communication means.

The disclosed methods, apparatuses, and systems should not be construedas limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsubcombinations with one another. The disclosed methods, apparatuses,and systems are not limited to any specific aspect or feature orcombination thereof, nor do the disclosed embodiments require that anyone or more specific advantages be present or problems be solved.

Theories of operation, scientific principles or other theoreticaldescriptions presented herein in reference to the apparatuses or methodsof this disclosure have been provided for the purposes of betterunderstanding and are not intended to be limiting in scope. Theapparatuses and methods in the appended claims are not limited to thoseapparatuses and methods that function in the manner described by suchtheories of operation.

Although the operations of some of the disclosed methods are describedin a particular, sequential order for convenient presentation, it shouldbe understood that this manner of description encompasses rearrangement,unless a particular ordering is required by specific language set forthbelow. For example, operations described sequentially can in some casesbe rearranged or performed concurrently. Moreover, for the sake ofsimplicity, the attached figures cannot show the various ways in whichthe disclosed systems, methods and apparatuses can be used inconjunction with other systems, methods and apparatuses.

Additionally, the description sometimes uses terms like “produce” and“provide” to describe the disclosed methods. These terms are high-levelabstractions of the actual computer operations that are performed. Theactual computer operations that correspond to these terms will varydepending on the particular implementation and are readily discernibleby one of ordinary skill in the art.

Having illustrated and described the principles of the illustratedembodiments, the embodiments can be modified in various arrangementswhile still remaining faithful to the concepts described above. In viewof the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. We thereforeclaim as our invention all that comes within the scope of these claims.

We claim:
 1. A method of displaying anaglyph video in place of stereo 3Dvideo, the method comprising: receiving via a video pipeline, stereo 3Dvideo data employing a YUV color space, wherein the video pipelinecomprises a plurality of video pipeline components, wherein theplurality of video pipeline components comprise at least a videoprocessor and a display; using a computing device, generating anaglyphvideo data from the stereo 3D video data, the generating comprising:unpacking the stereo 3D video data to a left view and a right view; andcombining the left view and the right view into a single view, theanaglyph video data comprising the single view, wherein: the combininguses anaglyph transform matrices that correspond to a configuration ofthe plurality of video pipeline components associated with the receivedstereo 3D video data; coefficients for the anaglyph transform matricesare selected based on one or more configuration characteristicsassociated with the plurality of video pipeline components, the one ormore configuration characteristics including at least one of a chromasampling scheme and a chroma sampling arrangement, and configurationcharacteristics of one or more of a video capture device, a displayand/or viewing glasses; and the resulting anaglyph video data has atleast a minimum display aperture and a pixel aspect ratio to bedisplayed on the display; and displaying video encoded in the stereo 3Dvideo data in anaglyph form.
 2. The method of claim 1, comprising:adjusting one or both of minimum display aperture and pixel aspect ratioassociated with the received stereo 3D video data using the anaglyphtransform matrices.
 3. The method of claim 1, wherein the anaglyphtransform matrices include anaglyph transform matrix coefficients thatdepend on characteristics of components within the video pipeline. 4.The method of claim 3, wherein the video encoded in the stereo 3D videodata is displayed on a display and at least one of the anaglyphtransform matrix coefficients depend on one or more characteristics ofthe following: the display, a video capture device used to capture thevideo encoded in the stereo 3D video data and anaglyph glasses used toview the display.
 5. The method of claim 1, the method furthercomprising: receiving one or more modified anaglyph transform matrixcoefficients in response to a change in the video pipelineconfiguration; and generating the anaglyph video data using the one ormore modified anaglyph transform matrix coefficients.
 6. The method ofclaim 5, wherein the change in the video pipeline configurationcomprises a change in a display, a change in a video capture device or achange in anaglyph glasses.
 7. The method of claim 5, further comprisingreceiving the one or more modified anaglyph transform matrixcoefficients from a component of the video pipeline.
 8. The method ofclaim 7, wherein the one or more modified anaglyph transform matrixcoefficients are for use in generating anaglyph video data using a firstcolor space and chroma sampling combination, the method furthercomprising transforming the one or more modified anaglyph transformmatrix coefficients for use in generating anaglyph video data using asecond color space and chroma sampling combination.
 9. The method ofclaim 1, wherein the stereo 3D video data employs 4:2:0 chromasubsampling and the anaglyph video data is generated using the followingformula: ${\begin{pmatrix}{Y\; 0} \\{Y\; 1} \\{Y\; 2} \\{Y\; 3} \\U \\V\end{pmatrix} = {{{ML}\begin{pmatrix}{{YL}\; 0} \\{{YL}\; 1} \\{{YL}\; 2} \\{{YL}\; 3} \\{UL} \\{VL}\end{pmatrix}} + {{MR}\begin{pmatrix}{{YR}\; 0} \\{{YR}\; 1} \\{{YR}\; 2} \\{{YR}\; 3} \\{UR} \\{LR}\end{pmatrix}}}},$ wherein YL0-YL3 are luma samples of the left view, ULand VL are chroma samples of the left view; YR0-YR3 are luma samples ofthe right view; UR and VR are chroma samples of the right view, Y0-Y3are luma samples of the anaglyph video data; and U and V are chromasamples of the anaglyph video data; ML and MR are anaglyph transformmatrices having the form ${{Mx} = \begin{pmatrix}a & 0 & 0 & 0 & b & c \\0 & a & 0 & 0 & b & c \\0 & 0 & a & 0 & b & c \\0 & 0 & 0 & a & b & c \\{d\; 0} & {d\; 1} & {d\; 2} & {d\; 3} & e & f \\{g\; 0} & {g\; 1} & {g\; 2} & {g\; 3} & h & i\end{pmatrix}},$ wherein a, b, c, d0-d3, e, f, g0-g3, h and i areanaglyph transform matrix coefficients.
 10. The method of claim 1,wherein the stereo 3D video data is encoded using 4:2:2 chromasubsampling and the anaglyph video data is generated using the followingformula: ${\begin{pmatrix}{Y\; 0} \\{Y\; 1} \\U \\V\end{pmatrix} = {{{ML}\begin{pmatrix}{{YL}\; 0} \\{{YL}\; 1} \\{UL} \\{VL}\end{pmatrix}} + {{MR}\begin{pmatrix}{{YR}\; 0} \\{{YR}\; 1} \\{UR} \\{VR}\end{pmatrix}}}},$ wherein YL0 and YL1 are luma samples of the leftview, UL and VL are chroma samples of the left view, YR0and YR1 are lumasamples of the right view, UR and VR are chroma samples of the rightview, Y0 and Y1 are luma samples of the anaglyph video data, U and V arechroma samples of the anaglyph video data; and ML and MR are anaglyphtransform matrices having the form: ${{Mx} = \begin{pmatrix}a & 0 & b & c \\0 & a & b & c \\{d\; 0} & {d\; 1} & e & f \\{g\; 0} & {g\; 1} & h & i\end{pmatrix}},$ wherein a, b, c d0, d1, e, f g0, g1, h and i areanaglyph transform matrix coefficients.
 11. A method for selecting avideo display format, the method comprising: receiving via a videopipeline, stereo 3D video data employing a YUV color space at acomputing device, wherein the video pipeline comprises a plurality ofvideo pipeline components, wherein the plurality of video pipelinecomponents comprise at least a video processor and a display; selectingthe video display format from at least two of the following formats:stereo 3D video, anaglyph video and monoscopic video, the selectingbased on availability of at least one processing resource for processingthe received stereo 3D video data into the selected video displayformat, wherein the availability is determined prior to the processing,and the processing is based on one or more configuration characteristicsassociated with the plurality of video pipeline components, wherein: theone or more configuration characteristics including at least one of achroma sampling scheme and a chroma sampling arrangement, andconfiguration characteristics of one or more of a video capture device,a display and/or viewing glasses; and the resulting video data in theselected video display format has at least a minimum display apertureand a pixel aspect ratio to be displayed on the display; and displayingvideo encoded in the stereo 3D video data in the selected video displayformat.
 12. The method of claim 11, wherein the selecting comprisesselecting the video display format based on characteristics ofcomponents within a video pipeline.
 13. The method of claim 11, whereinthe video encoded in the stereo 3D video data is displayed on a displayand the selecting comprises selecting the video display format based oncharacteristics of the display.
 14. The method of claim 11, wherein theselecting comprises selecting the video display format based on whetherthe computing device is communicatively coupled to 3D viewing glasses.15. The method of claim 11, wherein the selected video display format isa first video display format, the method further comprising: selecting asecond video display format that is different from the first videodisplay format; and displaying the video encoded in the stereo 3D videodata in the second video display format.
 16. The method of claim 15,wherein the second video display format is selected automatically inresponse to a change in the display.
 17. The method of claim 11, furthercomprising: if the selected video display format is anaglyph video,converting the stereo 3D video data to anaglyph video data; and if theselected video display format is monoscopic video, converting the stereo3D video data to monoscopic video data.
 18. The method of claim 11,further comprising receiving user input indicating a user-selected videodisplay format, wherein the selecting comprises selecting theuser-selected video display format as the video display format.
 19. Oneor more computer-readable memory devices or storage devices storingcomputer-executable instructions for causing a computing device toperform a method, the method comprising: receiving via a video pipeline,stereo 3D video data employing a YUV color space, wherein the videopipeline comprises a plurality of video pipeline components, wherein theplurality of video pipeline components comprise at least a videoprocessor and a display; using a computing device, generating anaglyphvideo data from the stereo 3D video data, the generating comprising:unpacking the stereo 3D video data to a left view and a right view; andcombining the left view and the right view into a single view, theanaglyph video data comprising the single view, wherein: the combininguses anaglyph transform matrices that correspond to a configuration ofthe plurality of video pipeline components associated with the receivedstereo 3D video data; coefficients for the anaglyph transform matricesare selected based on one or more configuration characteristicsassociated with the plurality of video pipeline components, the one ormore configuration characteristics including at least one of a chromasampling scheme and a chroma sampling arrangement, and configurationcharacteristics of one or more of a video capture device, a displayand/or viewing glasses; and the resulting anaglyph video data has atleast a minimum display aperture or a pixel aspect ratio to be displayedon the display; and displaying video encoded in the stereo 3D video datain anaglyph form.
 20. The one or more computer-readable memory devicesor storage devices of claim 19, wherein the stereo 3D video data isencoded using 4:2:0 chroma subsampling and the anaglyph video data isgenerated using the following formula: ${\begin{pmatrix}{Y\; 0} \\{Y\; 1} \\{Y\; 2} \\{Y\; 3} \\U \\V\end{pmatrix} = {{{ML}\begin{pmatrix}{{YL}\; 0} \\{{YL}\; 1} \\{{YL}\; 2} \\{{YL}\; 3} \\{UL} \\{VL}\end{pmatrix}} + {{MR}\begin{pmatrix}{{YR}\; 0} \\{{YR}\; 1} \\{{YR}\; 2} \\{{YR}\; 3} \\{UR} \\{LR}\end{pmatrix}}}},$ wherein YL0-YL3 are luma samples of the left view, ULand VL are chroma samples of the left view; YR0-YR3 are luma samples ofthe right view; UR and VR are chroma samples of the right view, Y0-Y3are luma samples of the anaglyph video data; and U and V are chromasamples of the anaglyph video data; and ML and MR are anaglyph transformmatrices corresponding to a configuration of a video pipeline and havethe form: ${{Mx} = \begin{pmatrix}a & 0 & 0 & 0 & b & c \\0 & a & 0 & 0 & b & c \\0 & 0 & a & 0 & b & c \\0 & 0 & 0 & a & b & c \\{d\; 0} & {d\; 1} & {d\; 2} & {d\; 3} & e & f \\{g\; 0} & {g\; 1} & {g\; 2} & {g\; 3} & h & i\end{pmatrix}},$ wherein a, b, c, d0-d3, e, f, g0-g3, h and i areanaglyph transform matrix coefficients that depend on one or morecharacteristics of the following: a display, a video capture device andanaglyph glasses used for viewing the display, the method furthercomprising: modifying at least one of the anaglyph transform matrixcoefficients in response to a change in the video pipelineconfiguration; and generating the anaglyph video data using the modifiedanaglyph transform coefficients.